Beverage preparation machines are well known in the food science and consumer goods area. Such machines allow a consumer to prepare at home a given type of beverage, for instance a coffee-based beverage, e.g. an espresso or a brew-like coffee cup.
Today, most beverage preparation machines for in-home beverage preparation comprise a system made of a machine which can accommodate portioned ingredients for the preparation of the beverage. Such portions can be soft pods or pads, or sachets, but more and more systems use semi-rigid or rigid portions such as rigid pods or capsules. In the following, it will be considered that the beverage machine of the invention is a beverage preparation machine working a rigid capsule.
The machine comprises a receptacle for accommodating said capsule and a fluid injection system for injecting a fluid, preferably water, under pressure into said capsule. Water injected under pressure in the capsule, for the preparation of a coffee beverage according to the present invention, is preferably hot, that is to say at a temperature above 70° C. However, in some particular instances, it might also be at ambient temperature. The pressure inside the capsule chamber during extraction and/or dissolution of the capsule contents is typically about 1 to 6 bar for dissolution products, 2 to 12 bar for extraction of roast and ground coffee. Such a preparation process differs a lot from the so-called “brewing” process of beverage preparation—particularly for tea and coffee, in that brewing involves a long time of infusion of the ingredient by a fluid (e.g. hot water), whereas the beverage preparation process allows a consumer to prepare a beverage, for instance coffee within a few seconds.
The principle of extracting and/or dissolving the contents of a closed capsule under pressure is known and consists typically of confining the capsule in a receptacle of a machine, injecting a quantity of pressurized water into the capsule, generally after piercing a face of the capsule with a piercing injection element such as a fluid injection needle mounted on the machine, so as to create a pressurized environment inside the capsule either to extract the substance or dissolve it, and then release the extracted substance or the dissolved substance through the capsule. Capsules allowing the application of this principle have already been described for example in applicant's European patent no EP 1 472 156 B1, and in EP 1 784 344 B1.
Machines allowing the application of this principle have already been described for example in patents CH 605 293 and EP 242 556. According to these documents, the machine comprises a receptacle for the capsule and a perforation and injection element made in the form of a hollow needle comprising in its distal region one or more liquid injection orifices. The needle has a dual function in that it opens the top portion of the capsule on the one hand, and that it forms the water inlet channel into the capsule on the other hand.
The machine further comprises a fluid tank—in most cases this fluid is water—for storing the fluid that is used to dissolve and/or infuse and/or extract under pressure the ingredient(s) contained in the capsule. The machine comprises a heating element such as a boiler or a heat exchanger, which is able to warm up the water used therein to working temperatures (classically temperatures up to 80-90° C.). Finally, the machine comprises a pump element for circulating the water from the tank to the capsule, optionally though the heating element. The way the water circulates within the machine is selected via a selecting valve means, such as for instance a peristaltic valve of the type described in applicant's European patent application EP 2162653 A1.
When the beverage to be prepared is coffee, one interesting way to prepare the said coffee is to provide the consumer with a capsule containing roast and ground coffee powder, which is to be extracted with hot water injected therein.
Capsules have been developed for such an application, which are described and claimed in applicant's European patent EP 1 784 344 B1, or in European patent application EP 2 062 831.
In short, such capsules comprise typically, as illustrated in FIG. 1:                a hollow body and an injection wall which is impermeable to liquids and to air and which is attached to the body and adapted to be punctured by e.g. an injection needle of the machine,        a chamber containing a bed of roast and ground coffee to be extracted,        an aluminum membrane disposed at the bottom end of the capsule, closing the said capsule, for retaining the internal pressure in the chamber, the said membrane being associated with piercing means for piercing dispensing holes in the said aluminum membrane when said internal pressure inside the chamber reaches a certain predetermined value,        optionally, means configured to break the jet of fluid so as to reduce the speed of the jet of fluid injected into the capsule and distribute the fluid across the bed of substance at a reduced speed. It is critical for the user to know when the water level in the machine tank is too low to prepare a full beverage.        
The capsule body is a tri-dimensional complex element, comprising at its bottom part a step such that the aluminum membrane described above can be sealed onto the internal surface of said body, as illustrated in FIG. 1.
The capsule body is typically manufactured by thermoforming a sheet of plastic. In order to protect the capsule contents against gas and moisture degradation during storage, the capsule body is manufactured using a plastic which is generally a laminate comprising at least one gas and moisture barrier layer. Such a technical requirement prevents using an injection-moulding technique, because such an injection moulding technique does not allow the injection of a multilayer body wall.
The aluminum membrane described above provides a good barrier in the lower part of the capsule. And the top pierceable membrane (“injection wall” described above) is made with a gas and moisture impermeable material as well, which can be mono- or multilayer.
As can be understood, all materials are chosen as it is essential to guarantee the capsule be moist and gas barrier to protect its contents.
In-mould labelling (IML) is a label moulding technique used in blow moulded, injection moulded and thermoformed containers. In general an inner layer compatible with the plastic material partially melts to bond to a plastic structure formed inside the injection or thermoforming mould.
In general, the label is placed in the mould wherein it is held in place by vacuum or other dedicated positioning means. The mould is then closed and molten plastic resin is poured or injected into the mould in order to form the packaging container. Thereby, the adhesive of the label is activated due to the heat resulting from the injection of hot resin and thus, the label is adhered to the container, i.e. the label becomes moulded to the container wall.
EP 1440903 refers to a cartridge for the preparation of a beverage with a barrier coating applied by a number of mechanisms including in-mould labelling.
JP 10129737 A for example relates to a packaging container with an opening having oxygen gas barrier properties. Thereby, an inner wall of a side face of a bottomed container main body and an inner wall of a bottom thereof is provided with in-mould labels for improving the oxygen gas barrier properties of the packaging container.
Furthermore, GB 1348370 discloses a container comprising a structure or frame, made of a rigid or semi rigid material, which is used as a support for applying a softer material, like for instance a film by an in-mould labelling technique so as to obtain a container
FR 2700493 A is a French patent application that also discloses a container that is made by injecting a rigid frame onto which a label is attached to complete the container body, for instance by in-mould labelling.
Such a IML technique provides advantages industrially, in terms of production rate, practicality, and also as it helps reducing the amount of packaging material that is used, hence being economically, and ecologically friendly.
It is therefore one main objective of the present invention to develop a capsule that can be produced by IML, and a manufacturing process for making it, that provides all the advantages of the IML production cited above, while achieving high gas and moisture protection of the capsule contents.